.active {
    color: brown;
}

.main_box {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.router {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: calc(100% - 60px);
}

.footer_box {
    display: flex;
    justify-content: space-around;
    align-items: center;
    height: 50px;
    border-top: 1px solid #dadada;
}